The Tower Bridge, with a cruise ship docked alongside a warship/museum in front of it.
The old-style buildings on the right edge of the photo are a neat shopping mall area with a beautiful courtyard in the middle. We ended up having lunch there shortly after this photo was taken. Which is a bit of a funny story in itself...
The bus stopped in front of a 'dungeon' tour right before crossing the Tower Bridge. The dungeon was essentially a haunted-house attraction, and it looked like a lot of fun. So we all hopped off the bus and bought tickets for it from the bus company. See, by buying the tickets from the bus company, we could avoid the long ticket line in front of the attraction and go into the group/reservation entrance on the side.
But when we got inside, Rachel decided she wasn't interested in seeing the dungeon tour. She basically refused to take another step farther inside, and no amount of talking could convince her otherwise. So we had to go back out and scalp the tickets to some people waiting in line. It turns out that the people we sold the tickets to were from the US as well (San Diego if I recall correctly), and were there because their daughter had chickened out the last time. This was their second try. :-)
So we walked down the street to that aforementioned mall, and had some fantastic quiche in a small French restaurant before getting back on the next bus.